Manchester City manager Roberto Mancini has accused Turkish referee Cuneyt Cakir of making "a big mistake" when he sent Manchester United winger Nani off against Real Madrid in the Champions League on Tuesday.

The City boss said he sympathises with his United counterpart Sir Alex Ferguson, who was angry with Cakir's decision after his side, 1-0 up when Nani was dismissed, eventually lost 2-1 to Real and were knocked out of the Champions League.

The Portugal international was shown the red card for a challenge on Alvaro Arbeloa that Mancini believes did not even merit a caution.

"Sometimes the referee can make a mistake, and for me this was a big mistake," he said. "Nani didn't deserve a yellow card. It was nothing. Nani tried to take the ball. He didn't see Arbeloa. I don't know what the referee saw."

Mancini said that, like Ferguson, he has suffered from decisions he has not agreed with, citing two red cards City captain Vincent Kompany has received in the past 14 months.

"I can understand Ferguson's frustration because it's the same that happened with Vinnie in the FA Cup against Manchester United last year and with Vinnie against Arsenal this year," he said.